a. Field of the Invention
The invention relates to a liquid crystal device having reduced power consumption and a driving method for the liquid crystal device.
b. Description of the Related Art
FIG. 1 shows a schematic diagram illustrating a conventional reflective-type TFT LCD. Referring to FIG. 1, in the reflective-type TFT LCD 100, a stack of a first metal layer M1 and a second metal layer M2 is used to form a transistor T and a storage capacitor Cst. A reflective sheet 104 disposed on one side of an array substrate 102 is allowed to reflect ambient light I1 to reduce power consumption. FIG. 2 shows a schematic diagram illustrating a conventional transflective-type TFT LCD. Referring to FIG. 2, in the transflective-type TFT LCD 200, each pixel has a transmissive region and a reflective region. The reflective region is formed by a reflective sheet 204 disposed on one side of an array substrate 202. In case the ambient light I1 is not sufficient to provide proper brightness, backlight I2 is used and emits from the transmissive region to increase brightness. In comparison, when the ambient light I1 is sufficient, the backlight I2 is turned off to reduce power consumption and the ambient light I1 is reflected by the reflective region.
However, these conventional designs do not disclose optimum dimensions of the storage capacitor and the corresponding driving scheme to further reduce power consumption.